Product tracking and security through design methodology in additive manufacturing 1 Specific Aims Additive manufacturing (AM) is increasingly being used in the medical for applications as diverse as printing prosthesis and implants of ceramic and metallic materials and even organs using soft materials and live tissue (bioprinting). In AM, a computer aided design (CAD) file is processed and sent to a 3D printer to print the desired shape, which reduces time and cost compared to the traditional polymer or metal working methods. Figure 1a presents an example of a mandibular reconstruction plate design and Figure 1b shows the 3D printed plate for fixation in a patient?s jaw. This exciting new manufacturing method comes with new challenges. All steps of the AM process chain, including the final printing step, are based on software programs and are exposed to cybersecurity threats. Stolen CAD files can be used to print parts of (a) exactly the same quality as the original component and make it difficult to separate originals from counterfeits or (b) exactly the same geometry but with inferior materials, which may not have the same performance. Given the cybersecurity scenario that even the most protected federal government assets and corporations have been breached recently, it is likely that the designs developed by biomedical researchers and companies are exposed to the same risks. In the biomedical and medical fields, inferior components can pose significant risk to the health and wellbeing of the patient. The stolen CAD files can make their way to countries where neither intellectual property protections (a) (b) are strong nor tracking of implants is possible. Figure 1. A mandibular reconstruction plate: (a) a CAD model Given such scenario, the present project is and (b) a manufactured plate applied to the locations where aimed at developing tools to embed security jaw injuries, disorders, or mandibular deformities and fractures take place. Image courtesy: Dr. Paulo Coelho, NYU features in the CAD files so that the parts School of Medicine. printed from the stolen CAD files can be identified. The project is based on a new design methodology developed by the PI Zeltmann and co-PI Gupta, which is now patent-pending and formed the basis for establishing 3DP Security, Inc. for its commercialization. This new methodology takes advantage of the layer- by-layer manufacturing of AM processes and has potential for developing security features that will be invisible to unsuspecting people. In the presence of such features, the component will print in high quality only under a pre-determined set of conditions, while any other condition will result in a severely defective component that will be unsuitable for use. This design methodology is used in the present proposal to print identification codes in the genuine implants. Specific Aim #1 An identification code will be embedded in the mandibular implant. A process will be developed so that the embedded code can be printed in the material only under certain file processing conditions for 3D printing. All other processing conditions will ignore the presence of the code. This scheme will also help in identification of genuine products from counterfeits, which may have been printed from stolen files and possibly using inferior quality materials. The code will be sliced into several sections and embedded in different layers of the material by taking advantage of the layer by layer manufacturing process. Such possibilities are unique to additive manufacturing and do not exist in other traditional manufacturing methods such as casting and forging. Mechanical tests will be conducted to ensure that the embedded code does not compromise the quality of the product in any way. Tensile tests will be conducted on the specimens to determine the properties of the implant with and without the embedded codes. Specific Aim #2 A software utility will be developed that will take the STL files of the implant design as inputs and embed the security code in them. This utility will first generate a desired tracking code, slice this code into several parts, and then embed it in the STL file in such a way that each slice of the code prints in a different layer in the implant. The Phase I effort will demonstrate the utility developed in MATLAB. The utility will take into account the 3D printing technology used for that product and the processing parameter in order to develop the desired embedding scheme.